Casein product and process of making



Fein-15,L 1938.' lH.v. puNHAM 2,108,582

` CAsErN PRCJDUGTy AND PRocEss voF MAKING Filed Ap'rii 2e, 1935 WET oASf-:m' AND FuLLgR l I I l l l l z l l framed Fea-15, 193s v uilill'rlarn' .STATES casein PnonUc'r AND raoeEss 0F' MAKING I ,y Henry V. Dunham, Bainbridge, N.

Application April 26, 1935, Serial No. 18,436` In Great Britain December 8, 1934 n1a claims. (01.' 134-239) 'I'he present invention relates to the manufacture of products, from "acid precipitated" casein,

5 cation Serial No. 644,752, ledNovember 22, 1932 ,v

(now Patent 2,005,730) of which the present case is in part a continuation and further development. 4

In accordance with the present invention I produce very intimate mixtures of casein and extending materials, fillers, softening agents, modifying agents, or the like, one or several (all hereinafter embraced under the generic term "fillers" for brevity), by treating moist casein andj the said added substances, in a screw press or the like, said screw press being, if desired,l supplied with a heating `and/or cooling jacket. During this operation the materials are very thoroughly blended together,- under high pressure, and within the outlet end of the screw press there is preferably provided one or more perforated plates or grids vor screens, and the mixture is extruded from the said screw press preferably in the form of a thin ribbon (a forinhaving at least one very small dimension) and theextruded material is thereafter preferably dried and ground. The mixture which is to betreated in the said screw press may be' dried casein to whichv a fraction of its own weight of water has been added, and the casein allowed to absorb this water, then the extending material or other filler, etc., is added, preferably (in most cases) in a dry condition, the components mixed together, and the mixture introduced at the inlet of the extruding machine.

The annexed drawing illustrates conventionally anapparatus of wellknown construction suitable for carrying out the kneading and extruding I operations, this apparatus being such as has long beenI usedl in the industry of casein plastics. Rennet casein, is commonly used in plastics, but in the present invention I use acid-precipitated casein exclusively.

Within the casing I0 isi mounted 'a rotating screw II, whichforces the material towards the Y wet casein and nller is introduced through the hopper I2 where it is picked up by the convolutions of the rotating screw II, and fo ced under i high pressure through the perfora plates shown respectively at I3 and I4, which are perforated with various sized holes. The'passage I5 between these two plates may taper somewhat as shown, and the passage I6 leading to the extrusion outlet IIA also tapers. -The outlet II may be in the form of a slot having one small dimension,

right inthe drawing. Thel mixture comprising.

for example this may be half an inch wide anda sixteenth of an inch high, to produce a ribbon, or it could have one or more small holes to produce one or several small strings or "worms.

lAt I 8 and I9 are shown suitable jackets for'con- 5f taining heating or cooling uids, such as steam, hot water, warm water, cold brine or the like. These jackets are provided with suitable inlet and outlet pipes 20 and 2| as well known in the art. Y

After the material extruded at I'I has been 10 dried, and preferably ground to a coarse or ne powder, it can be mixed with various chemicals to serve fas casein solvents for the manufacture of glue, adhesives, sizings, paints, emulsions, or various other final products.

It will be understood that in the convolutions of the screw, as well as in passing through the perforations in plates I3 and III, and also in passingthrough the vtapering passages I5 and I6,

and the extrusion outlet II, the mixture may be 20 u nder very high pressure.

As examples of the fillers I mention wood-flour, Whiting, clays, pigments, softening agents, waxes, resins, and modifying agents such as dextrine, starch or starchy materials, proteinous sub-v 25 stances such as hide glues, animal glues, vegetable seedmeals, vsuch as peanut meal, soymeal and the like, orthe isolated proteins from said meals, without in any way-restricting myself to these particular substances. Many examples of suitable4 30 substances to be added might be given, but the following are mentioned as illustrative of suitable types. Mineral fillers such as barytes, clay, talc, gypsum, lithopone, zinc oxide, titanium 'white pigments'and bentonite as well as all other pig`- 35 ment types, also any or all or a mixture of colors like ochres,l iron oxides, Sienna.,l burnt umher, vermilln, lead and zinc pigments, chrome pigments and yany other water insoluble or substantially `1water insoluble'pigments' ordinarily usedv in the 40 making of paints. f Also I may include .modifying agents of the nat-ure of soaps, e. g. the lineolates, stearates, oleates, resinates,palmitates, and other soaps of the metals or non-metals such as sodium, am- 45 monium, potassium, cobalt, copper, calcium, aluminum, zinc, iron, etc., also various waxes4 and soft balsams such as balsam of r, bayberry wax,- carnauba'. wax, Montan wax, wool fat, China vegetable wax, Japan wax, and the like. Also'water- 60 soluble gums such as gum'arabic, gum kino, gum

kai'aya and the like as well as low melting 'point resins, ester gums', shellac, synthetic resins, softening agents like-glycerin, glycol, ethylene glycol, di-'ethylene glycol and-other polymers, the 4vw mixing the wet casein with the filler.

Example l.

various starches, glues, dextrines, blood albumen, dried blood.

The materials mentioned in the two preceding paragraphs (and others mentioned in some of the examples given below) will hereinafter be referred to under the generic term "ller.

The proportions of the components can vary,

between wide limits. Ordinary dry casein may contain about 8 to 11% of moisture. There may be added to this, about 15l to 25% of water, to form the wet casein, which may contain about 23 to 36% of water. An undried casein or partly dried casein of this moisture content could be employed, where available. With the wet casein may be used about 10 to 200%, more or less, of one or more of the above, (or analogous) fillers or 1 :ixtures thereof.

I have referred above to flrst mixing the casein with a small amount of water and allowing this to stand, stirring the mixture at intervals if desired, until the casein has absorbed the water, and then In other cases the casein, ller and water are simply thrown together into a tumbling barrel or other mixing device, and then fed to the hopper I2.

I give the following examples, for the purpose of illustration, but not as restricting the invention thereto.

'15 pounds of dry commercial caseinin the form of a powder are mixed with 25 pounds of water, and the mass stirred occasionally until the casein has absorbed the said amount of water. 'I'hen 25 pounds -of finely ground wood our are added, and the mass roughly mixed. It is then fed into the hopper I2 of the extrusion press, the `jackets I8 and I9 being filled with warm water at say 60 to '70 C., andthe extruded material is then dried, and ground to a ne powder.

During the mixing and kneading process the casein and wood flour will be found to have been very completely and thoroughly mixed together, into the form' of a thoroughly homogeneous mixture. A mixture can be produced which is far more homogeneous than any mixture of these materials produced by the commonly used mixing methods.

'I'he dried and powdered lmaterial can thereafter be mixed in an ordinary mixer, with soda,

lime, sodium fluoride, borax, trisodium phos' bodied liquid material with the nely ground wood flour thoroughly suspended in the same in a uniform manner, which can be applied by ordinary glue spreading machines, to veneers for making plywood, or a liquid of thinner consistency which can be applied to paper as a coating.-

Example 2 'l5 parts of-dry ground casein, 15 parts of finely powdered dry clay and 20 -parts of water. These are mixed, kneaded, extruded and dried -as in After drying, the dry, POwdered product can be used as a -distemper paint, by being mixed with alkali, lime and the like, and the final mixture subsequently dissolved in If desired. a

much larger amount of the powdered dry clay can be used than indicated above. Coloring pigments or dyes can also be added to the initial material or to the extruded and dried material.

The clay is so uniformly distributed through the mass of casein, when 'in a softened condition in Ithe screw press that when the dried paint is mixed with water, it will not settle as badly as when the paint-is made by the conventional methods. y

In a modification of this example, 20 parts of powdered talc can be used in place of the dry clay.

Example 3 Pounds Casein -i 'l5 Dry chrome yellow pigment 50 Water ---c i 35 The above materials are mixed together, and allowed to stand for a time for the water to be absorbed by the casein' and dry yellow pigment, or the water and casein can first be mixed together, allowed to stand for the water to be absorbed and the dry lpigment then added. The mixture is then passed through the extrusion device as above referred to, the product is dried and ground to a fine powder.

For making an artists paint this powder can be mixed with sufcient alkaline material in the dry form to act as a solvent for the casein when water is added. The intimate intermingling of the pigment with the casein in the initial process produces a very uniform nal liquid product.

'A suitable amount of the colored powder, either alone or 4in admixture with 4a casein solvent can also be blended with compositions of the type described in Example 2. It is to be understood that instead of the yellow pigment, pigments of various other colors can be similarly employed.

Example 4 Pounds Casein 75 Finely shredded Japan wax 10 Water 20 The above mixture is extruded, dried and ground to a fine powder.

Whenfthis dry powder is added to a mixture of 'water and an alkaline" material, or when the said dry powder is mixed with alkali and subsequently added to water, the casein will dissolve. There is produced an extremely uniform mixture or emulsion of dissolved casein and a softening agent, namely Japan wax, which emulsion is uniform and relatively stable, andcan be used as a coating, where soft flexible coatings of casein or casein mixtures are desired.

It is of course to be understood that pigments, solid flllers or extending agents and the like can be added, for example before or after the extruding operation.

Example 5 Pounds Ground casein 'I5 Powdered parailine wax 15 Water 20 .The treatment is as in Example 4. The dissolved product from this example gives a more or less water-resisting and oil-resisting coating, and while the paramne wax is not saponied by the action of casein solvents, it is thoroughly emulsiiled, and the emulsion remains relatively stable over a considerable period.

In this example, powdered steoric acid can be used instead of parafline wax.- The stearlc acid may be in part acted upon by the alkali used in dissolving the casein or in case strong alkalies are used, the whole of the stearic acid can be conyit) verted into a soap. Any unconverted stearic acid would form a stable emulsion in the casein solution.

` Example 6 Pounds -Casein 75 Glycerine 15 Water l 20 The above materials are mixed, extruded, dried and comminuted. Sufficient `alkali is added to -dissolve the casein, and the mixtureis added to water. In place of the glycerine, ethylene glycol or diethylene glycol or other glycols can be employed. The glycerine or equivalent material gives more flexibility to the product obtained by applying the casein solution and drying the same,

on paper, cloth, artiiicial leather, leathervor the like and also acts to increase the adhesive quality, for example when casein solution is used for uniting glassine paper -to' paper, cardboard, coated cardboard or the like.

It will be understood that the addition of waxes, fats, glycerine or similar softeners does not preclude the addition of solid insoluble fillers such as above referred to, but the waxy or fatty material or the softener can be'used in addition to the said solid illlers vor the like;

In the examples in which solid llers such as wood. iiour are used, it will be understood that Water pigments or other coloring agents can also be added if desired.

" A`Example 7 Pounds Ground casein 75 Cassava `starch 20 The"ingredients are mixed together, extruded,

dried and ground. 'Ifhe powdered material `is mixed with alkali'as a casein solvent, and this mixture subsequently dissolved in water. By this process the starch becomes very thoroughly blended with the casein vin the extruding operation, and a very homogeneous product is thereby produced. There may be sulcient alkali' present to constitute a solvent or converting agent `for the starch, or the liquid may be heated, to break up the rstarch granules, thereby. overcoming the tendency for the 'starch to separate from the casein, which ordinarily exists when ground casein andv ground starch are mechanically mixed together with mild alkali.

` Add ,the water to the casein, let it stand for 15 or 20 minutesfor the 'water-to be absorbed,` then addthedry dextrine,' let it soften another 20` mlnuteswith mixing if desired. "I'hen mix, ex.

trude, dry and grind. In this manner dextrine can be uniformly distributed through the casein so that': on the subsequent addition of a caseinsolvent and water a uniform glue or sizing is oli-l tained which has very much less tendency to foam than is the case when` dry casein and dry dextrine witlithe necessary alkali are mixed together and dissolved in' water. j

. (solvent for the casein) are dry form, and addedto Wate Example 9 r Pounds Ground casein.; 75 Ground peanut meal 25 Water 20' Soak the casein in the water, then add the peanut meal, extrude, dry and grind. Add at least suflicient alkali to dissolve the casein portion when the powder is subsequently added to water. This powder is an intimate blend ofthe peanut meal and casein, which differs from a simple mechanical mixture of the two, and which on mixing with an alkali and Water'readily forms a homogeneous uid without lumping. The material can be used in the production Cof paints, sizings, glues and the like.

Example 10 Pounds Ground casein 75 Water v 20 Ground soybean meal 30 Remarks same as under Example No. 9.

The water is added to the ground casein. The

mass is mixed for'15 to 20 minutes, then the dry locust bean gum is sprinkled into the mixture and the mixing is continued fora few minutes. -The mass is then extruded, dried, ground and at least suiiicient alkaline material added to dissolve the casein portion of the mixture when the mixture is added to water; In this manner, one can get a very uniform distribution of the water-'soluble locust bean -gum throughout the casein mass. Locust bean gum'is useful as a sizing in the textile industry. Casein is also used largely in the` textile industry and this combination -gives a product-which dissolves quickly and uniformly without lumping and produces a desirable sizing for cloth.

Example 13 Pounds Casein- 75 Water 2W Hide glue, iineiyground 15 Add the water to the casein, mix 15 or 20 minutes, siftthe powdered hide glue into thewetted casein', mix 15 or 20, minutes, extrude, dry,

grind` and add sufficient casein 'solvent (e.

NaHCOa or borax) to dissolve the caseiny portion of the mixture when the same is subsequently added to water. In this example a uniforn mixture otcasein and hide glue is obtained-in a dry form, lwhich can be ilnely pulverizedand which then mixes readily with water in the presence of suiiicient alkali to dissolve the casein and which produces `under proper conditions a more tacky adhesive and will give amore-uniform solution than it is possible to obtain when ground hide glue and ground casein and the, alkaline material ixed together in the A'us Eample 14 Parts Ground casein 50 Clay 20 Glycerine 10 Cassava starch 10 lAnimal glue 10 Water 20 The casein, clay and starch are mixed together dry; the glycerine is added to the water and the water-glycerine mixture added to the dry mix in the usual way. Mix about 15 minutes then add the dry ground animal glue, mix 10 minutes.

.Or the casein first may be added to the water,

can be substituted for the examples given in every case.

One advantage of the present process is the production of extremelyl intimate mixtureswith casein. The grade of casein used in the present process is preferably that which is commonly used for` making glues and the like, namely casein obtained by precipitation with mineral or\organic acids. As is well known, rennet casein is uni suitable for making glues and sizings and is not Iused in the present invention. It .is to be understood that the present invention does not relate to the production of casein plastics, even though the material is in a plastic condition at the time of extrusion through the press illustrated in the drawing. 4In all cases the dried and comminuted product will be subsequently treated with a casein solvent (e. g. Water and alkali) which step ordinarily will be performed in making up the nal liquid product. The extruded mass is in al1 cases disintegrated, e. g. by comminuting, dissolving or the like. And the casein in the final product is soluble in ordinary casein solvents, e. g. soda, borax, ammonia, etc. all in dilute condition.

In the extruding operation I prefer to use a nozzle having a narrow rectangular .slot from which' the product emerges in the form of a ribbon, or a plurality of small holes, vwhereby the subsequent-crushing operation is facilitated but the product may also be extruded in the form of slender rods like wires or thin-walled tubes which likewise can be readily broken and reduced to a powder.

The term dry casein as used throughout this specification refers to the commercially dried material which ordinarily contains 6 `to 10% of moisture. 'I'he usel of casein dried to this point however lis not essential, and for some purposes the initial drying of the casein may be stopped when the vcasein contains a larger amount of water, say 15 to 20%, and in such cases proportionally less water is added to the initial mix.

truded-substance, grinding or crushing the same and then adding an alkaline material preferably a mild alkali, to react with the caseiny in the presence of water to be subsequently added, to form a solution of alkali-casein. The alkali if dry, can of course be added before the grinding or simultaneously therewith or an alkali can be added to the water before incorporating the powdere'd extruded material therewith.

'I'he vegetable seedmeal described above. such as peanut meal, soybean meal and the' like, may be the materials obtained by grinding the press cake remaining after expressing the oil from the respective seeds, this material still containing some oil, or the residue which remains after the oil has been completely extracted with solvents. This constitutes a modifying agent, as described above.

While I have referred to and illustrated a particular form of apparatus, namely a screw press extruding device, it is to be understood that various other forms of mixing, kneading and extruding devices can be employed for carrying vminuting the dry product, it may be feasible in some cases, to comminute the ribbon, and to then dry the comminuted material, followed, if desired, by further grinding. v

1. A process of making a liquid aqueous composition containing dissolved casein, which comprises thestep of mixingv and kneading together, acid-precipitated casein i containing waterv in amount sufficient to wet the same, the amount of said water-being less than the amount of said casein, and an insoluble filler, in the absence of substances capable of acting as/solubilizing ents for said casein, and the absence of substances capable of chemically hardening said casein, /such kneading'step being under substantial superat and iiller is obtained, extruding said mixture, and drying the same, and comminuting the dried product. r

2. A process of making a liquid aqueous composition containing dissolved casein, which comprises mixing and kneading together, acid-precipitated casein containing water inamount sufiicient to wet the same, the amount of said 65 mospheric pressure, and continuingl said operas( ltion until a complete admixture of said wet Acasein water being less than. the amount of'said casein,

and a iiller which does not chemically combine with said casein, such kneading s tep being under substantial superatmospheric pressure, and continuing said operation until a. complete admixture of the 'wet casein and filler is obtainemextruding the mixture, and drying the same, said operations being conducted in the absence of solubilizing agents for s'aid casein, and in the absence of hardening agents therefor, and thereafter mixing stantial superatmospheric pressure, and continuing said operation until a complete' admixture of the wet casein and. cellulosic material is obtained, extruding said mixture, and drying the same, and thereafter mixing said dried product with water and such an amount of an alkali as is capable of rendering the casein soluble in water.

4. A process whichcomprises intimately mixing and kneading together, under superatmospheric pressure, 75 parts of acid-precipitated casein in the presence of about 10 to 40 parts of water, with about l to 150 parts-of a filler, continuing the mixing and kneading operation until the materials are completely intermixed and extruding the mass and thereafter mixing the prodtion of the amount of actual casein, with a llerL 'uct with an alkali and water, whereby the casein dissolves to afford a liquid casein composition.

5.A In the manufacture of liquidA compositions containing dissolved casein, the herein described steps of mixing moist acid-precipitated casein in which the amount of water is only a minor fracin` the absence of added4 alkali, and thereafter kneading and extruding the mixture as a product having at least one small dimension, and thereafter drying the extruded material whereby subsequent .comminuting of the extruded material is facilitated, grinding thesame and admixing same with a reagentlwhich, inlthe presence of water, will constitute'a caseinfsolvent.

6. An intimate mixture of.. acid-precipitated casein and a filler,- kneaded together under pressure, extruded and dried. y y

v '1. A product as in claim, comminuted and mixed with an alkali.

, product.`

, 5 8. Asa new product. a thoroughly kneaded and substantially homogeneous extruded mixture 'of acid-precipitated casein with a iill'er,A such kneading and extrusion being performed in the absence of chemicals capable of acting as casein solvents and in the absence of chemicals capable 'of hardening-the case-in, such extruded product being comminuted and the casein therein being rapidly soluble in alkali solutions. 4

9.v yAs a new product, a thoroughly kneaded and substantially homogeneous extruded mixture of acid-precipitated casein with 'a iiller said mix- V ture being extruded in the absence of chemicals capable of reacting on casein, and in the absence of reaction products of casein with solubilizing agents or hardening agents, the casein in said product being rapidly soluble in alkali solution.

l0., A process of producing a liquid casein composition which comprises mixing and kneading together, acid-precipitated -ca'sein containing about to 35% of moisture and a ller extrudf i ing the well kneaded material and thereafter converting the product into va liquidlstate by mixing the same with an' alkali water.

11. As a new product, a thoroughly kneaded and substantially homogeneous extruded mixture consisting casein, a ller, and a small proportion of water.

12. A process of making a casein product for use .in liquid coating compositions and in which the casein will dissolve rapidly in alkali solution but not in water. comprising intimately mixing and kneading together under pressure a. mixture comprising '15 parts of acid-precipitated casein, about 10 to 40 parts of water, vand about 10 to 150 parts of a non-alkaline llergcontinuing solubility of the casein, and extruding lthe mixture in the absence of chemicals capableof acting as hardening agents for casein and'in the absence of' chemicals capable oi! acting as solubilizing agents for casein, and comminuting the extruded HENRY v. DUNHAM.

substantially of acid-precipitatedv `,the mixing and kneading to increase the rate of 

